Answer: D. relatively inexpensive and readily available
Fossil fuels are non-renewable sources of energy these resources formed by the geological processes occurring in the earth. It takes millions of years for their formation. These includes coal, petroleum, and natural gas. Unfortunately, the distribution of these resources is not even in the regions of the world but efforts have been done by the humans to make them available everywhere. They are relatively inexpensive and readily available this contributes to the majority of the world's energy use.